diff --git a/browser/components/extensions/test/xpcshell/test_ext_browsingData_passwords.js b/browser/components/extensions/test/xpcshell/test_ext_browsingData_passwords.js
index d39b5df05f79..4e8e498b8f82 100644
--- a/browser/components/extensions/test/xpcshell/test_ext_browsingData_passwords.js
+++ b/browser/components/extensions/test/xpcshell/test_ext_browsingData_passwords.js
@@ -9,8 +9,8 @@ const OLD_HOST = "http://mozilla.org";
 const NEW_HOST = "http://mozilla.com";
 const FXA_HOST = "chrome://FirefoxAccounts";
 
-function checkLoginExists(host, shouldExist) {
-  const logins = Services.logins.findLogins(host, "", null);
+async function checkLoginExists(origin, shouldExist) {
+  const logins = await Services.logins.searchLoginsAsync({ origin });
   equal(
     logins.length,
     shouldExist ? 1 : 0,
@@ -19,7 +19,7 @@ function checkLoginExists(host, shouldExist) {
 }
 
 async function addLogin(host, timestamp) {
-  checkLoginExists(host, false);
+  await checkLoginExists(host, false);
   let login = Cc["@mozilla.org/login-manager/loginInfo;1"].createInstance(
     Ci.nsILoginInfo
   );
@@ -27,7 +27,7 @@ async function addLogin(host, timestamp) {
   login.QueryInterface(Ci.nsILoginMetaInfo);
   login.timePasswordChanged = timestamp;
   await Services.logins.addLoginAsync(login);
-  checkLoginExists(host, true);
+  await checkLoginExists(host, true);
 }
 
 async function setupPasswords() {
@@ -62,27 +62,27 @@ add_task(async function testPasswords() {
     extension.sendMessage(method, {});
     await extension.awaitMessage("passwordsRemoved");
 
-    checkLoginExists(OLD_HOST, false);
-    checkLoginExists(NEW_HOST, false);
-    checkLoginExists(FXA_HOST, true);
+    await checkLoginExists(OLD_HOST, false);
+    await checkLoginExists(NEW_HOST, false);
+    await checkLoginExists(FXA_HOST, true);
 
     // Clear passwords with recent since value.
     await setupPasswords();
     extension.sendMessage(method, { since: REFERENCE_DATE - 1000 });
     await extension.awaitMessage("passwordsRemoved");
 
-    checkLoginExists(OLD_HOST, true);
-    checkLoginExists(NEW_HOST, false);
-    checkLoginExists(FXA_HOST, true);
+    await checkLoginExists(OLD_HOST, true);
+    await checkLoginExists(NEW_HOST, false);
+    await checkLoginExists(FXA_HOST, true);
 
     // Clear passwords with old since value.
     await setupPasswords();
     extension.sendMessage(method, { since: REFERENCE_DATE - 20000 });
     await extension.awaitMessage("passwordsRemoved");
 
-    checkLoginExists(OLD_HOST, false);
-    checkLoginExists(NEW_HOST, false);
-    checkLoginExists(FXA_HOST, true);
+    await checkLoginExists(OLD_HOST, false);
+    await checkLoginExists(NEW_HOST, false);
+    await checkLoginExists(FXA_HOST, true);
   }
 
   await extension.startup();
diff --git a/browser/components/migration/tests/marionette/test_refresh_firefox.py b/browser/components/migration/tests/marionette/test_refresh_firefox.py
index b3170d270de7..ea5d6bce99e8 100644
--- a/browser/components/migration/tests/marionette/test_refresh_firefox.py
+++ b/browser/components/migration/tests/marionette/test_refresh_firefox.py
@@ -244,13 +244,13 @@ class TestFirefoxRefresh(MarionetteTestCase):
         )
 
     def checkPassword(self):
-        loginInfo = self.marionette.execute_script(
+        loginInfo = self.runAsyncCode(
             """
-          let ary = Services.logins.findLogins(
-            "test.marionette.mozilla.com",
-            "http://test.marionette.mozilla.com/some/form/",
-            null, {});
-          return ary.length ? ary : {username: "null", password: "null"};
+          let [resolve] = arguments;
+          Services.logins.searchLoginsAsync({
+            origin: "test.marionette.mozilla.com",
+            formActionOrigin: "http://test.marionette.mozilla.com/some/form/",
+          }).then(ary => resolve(ary.length ? ary : {username: "null", password: "null"}));
         """
         )
         self.assertEqual(len(loginInfo), 1)
diff --git a/services/fxaccounts/FxAccountsStorage.sys.mjs b/services/fxaccounts/FxAccountsStorage.sys.mjs
index b3b66c56ac2d..24c85dbc2de9 100644
--- a/services/fxaccounts/FxAccountsStorage.sys.mjs
+++ b/services/fxaccounts/FxAccountsStorage.sys.mjs
@@ -498,11 +498,10 @@ LoginManagerStorage.prototype = {
       if (!this._isLoggedIn) {
         return false;
       }
-      let logins = Services.logins.findLogins(
-        FXA_PWDMGR_HOST,
-        null,
-        FXA_PWDMGR_REALM
-      );
+      let logins = await Services.logins.searchLoginsAsync({
+        origin: FXA_PWDMGR_HOST,
+        httpRealm: FXA_PWDMGR_REALM,
+      });
       for (let login of logins) {
         Services.logins.removeLogin(login);
       }
@@ -554,11 +553,10 @@ LoginManagerStorage.prototype = {
         ""
       ); // aPasswordField
 
-      let existingLogins = Services.logins.findLogins(
-        FXA_PWDMGR_HOST,
-        null,
-        FXA_PWDMGR_REALM
-      );
+      let existingLogins = await Services.logins.searchLoginsAsync({
+        origin: FXA_PWDMGR_HOST,
+        httpRealm: FXA_PWDMGR_REALM,
+      });
       if (existingLogins.length) {
         Services.logins.modifyLogin(existingLogins[0], login);
       } else {
@@ -590,11 +588,10 @@ LoginManagerStorage.prototype = {
         throw new this.STORAGE_LOCKED();
       }
 
-      let logins = Services.logins.findLogins(
-        FXA_PWDMGR_HOST,
-        null,
-        FXA_PWDMGR_REALM
-      );
+      let logins = await Services.logins.searchLoginsAsync({
+        origin: FXA_PWDMGR_HOST,
+        httpRealm: FXA_PWDMGR_REALM,
+      });
       if (!logins.length) {
         // This could happen if the MP was locked when we wrote the data.
         log.info("Can't find any credentials in the login manager");
diff --git a/services/fxaccounts/tests/xpcshell/test_loginmgr_storage.js b/services/fxaccounts/tests/xpcshell/test_loginmgr_storage.js
index 50a236918e95..3b1149845a15 100644
--- a/services/fxaccounts/tests/xpcshell/test_loginmgr_storage.js
+++ b/services/fxaccounts/tests/xpcshell/test_loginmgr_storage.js
@@ -29,12 +29,11 @@ function setLoginMgrLoggedInState(loggedIn) {
 
 initTestLogging("Trace");
 
-function getLoginMgrData() {
-  let logins = Services.logins.findLogins(
-    FXA_PWDMGR_HOST,
-    null,
-    FXA_PWDMGR_REALM
-  );
+async function getLoginMgrData() {
+  let logins = await Services.logins.searchLoginsAsync({
+    origin: FXA_PWDMGR_HOST,
+    httpRealm: FXA_PWDMGR_REALM,
+  });
   if (!logins.length) {
     return null;
   }
@@ -114,7 +113,7 @@ add_task(async function test_simple() {
     "scopedKeys not stored in clear text"
   );
 
-  let login = getLoginMgrData();
+  let login = await getLoginMgrData();
   Assert.strictEqual(login.username, creds.uid, "uid used for username");
   let loginData = JSON.parse(login.password);
   Assert.strictEqual(
@@ -139,7 +138,7 @@ add_task(async function test_simple() {
 
   await fxa.signOut(/* localOnly = */ true);
   Assert.strictEqual(
-    getLoginMgrData(),
+    await getLoginMgrData(),
     null,
     "login mgr data deleted on logout"
   );
@@ -158,7 +157,11 @@ add_task(async function test_MPLocked() {
     verified: true,
   };
 
-  Assert.strictEqual(getLoginMgrData(), null, "no login mgr at the start");
+  Assert.strictEqual(
+    await getLoginMgrData(),
+    null,
+    "no login mgr at the start"
+  );
   // tell the storage that the MP is locked.
   setLoginMgrLoggedInState(false);
   await fxa._internal.setSignedInUser(creds);
@@ -189,7 +192,11 @@ add_task(async function test_MPLocked() {
     "scopedKeys not stored in clear text"
   );
 
-  Assert.strictEqual(getLoginMgrData(), null, "login mgr data doesn't exist");
+  Assert.strictEqual(
+    await getLoginMgrData(),
+    null,
+    "login mgr data doesn't exist"
+  );
   await fxa.signOut(/* localOnly = */ true);
 });
 
@@ -235,7 +242,7 @@ add_task(async function test_consistentWithMPEdgeCases() {
   await fxa._internal.setSignedInUser(creds2);
 
   // We should still have creds1 data in the login manager.
-  let login = getLoginMgrData();
+  let login = await getLoginMgrData();
   Assert.strictEqual(login.username, creds1.uid);
   // and that we do have the first scopedKeys in the login manager.
   Assert.deepEqual(
@@ -264,7 +271,11 @@ add_task(async function test_consistentWithMPEdgeCases() {
 // the login manager.
 add_task(async function test_uidMigration() {
   setLoginMgrLoggedInState(true);
-  Assert.strictEqual(getLoginMgrData(), null, "expect no logins at the start");
+  Assert.strictEqual(
+    await getLoginMgrData(),
+    null,
+    "expect no logins at the start"
+  );
 
   // create the login entry using email as a key.
   let contents = {
diff --git a/services/sync/modules/engines/passwords.sys.mjs b/services/sync/modules/engines/passwords.sys.mjs
index b2e4cb4ad2f1..8dea5664be6f 100644
--- a/services/sync/modules/engines/passwords.sys.mjs
+++ b/services/sync/modules/engines/passwords.sys.mjs
@@ -14,8 +14,6 @@ import {
 } from "resource://services-sync/engines.sys.mjs";
 import { Svc, Utils } from "resource://services-sync/util.sys.mjs";
 
-import { Async } from "resource://services-common/async.sys.mjs";
-
 // These are valid fields the server could have for a logins record
 // we mainly use this to detect if there are any unknownFields and
 // store (but don't process) those fields to roundtrip them back
@@ -164,13 +162,11 @@ PasswordEngine.prototype = {
       return null;
     }
 
-    let logins = this._store.storage.findLogins(
-      login.origin,
-      login.formActionOrigin,
-      login.httpRealm
-    );
-
-    await Async.promiseYield(); // Yield back to main thread after synchronous operation.
+    let logins = await this._store.storage.searchLoginsAsync({
+      origin: login.origin,
+      formActionOrigin: login.formActionOrigin,
+      httpRealm: login.httpRealm,
+    });
 
     // Look for existing logins that match the origin, but ignore the password.
     for (let local of logins) {
diff --git a/services/sync/tests/unit/test_password_engine.js b/services/sync/tests/unit/test_password_engine.js
index e3c2576bc023..5c026ac5aff1 100644
--- a/services/sync/tests/unit/test_password_engine.js
+++ b/services/sync/tests/unit/test_password_engine.js
@@ -168,7 +168,9 @@ add_task(async function test_password_engine() {
     );
     await Services.logins.addLoginAsync(login);
 
-    let logins = Services.logins.findLogins("https://example.com", "", "");
+    let logins = await Services.logins.searchLoginsAsync({
+      origin: "https://example.com",
+    });
     equal(logins.length, 1, "Should find new login in login manager");
     newLogin = logins[0].QueryInterface(Ci.nsILoginMetaInfo);
 
@@ -208,7 +210,9 @@ add_task(async function test_password_engine() {
     props.setProperty("timePasswordChanged", localPasswordChangeTime);
     Services.logins.modifyLogin(login, props);
 
-    let logins = Services.logins.findLogins("https://mozilla.com", "", "");
+    let logins = await Services.logins.searchLoginsAsync({
+      origin: "https://mozilla.com",
+    });
     equal(logins.length, 1, "Should find old login in login manager");
     oldLogin = logins[0].QueryInterface(Ci.nsILoginMetaInfo);
     equal(oldLogin.timePasswordChanged, localPasswordChangeTime);
@@ -240,7 +244,9 @@ add_task(async function test_password_engine() {
       "Should update remote password for newer login"
     );
 
-    let logins = Services.logins.findLogins("https://mozilla.com", "", "");
+    let logins = await Services.logins.searchLoginsAsync({
+      origin: "https://mozilla.com",
+    });
     equal(
       logins[0].password,
       "n3wpa55",
@@ -372,7 +378,6 @@ add_task(async function test_sync_outgoing() {
     _("Remove the login");
     equal(collection.count(), 1);
     equal(Services.logins.countLogins("", "", ""), 2);
-    equal(Services.logins.findLogins("", "", "").length, 2);
     equal((await Services.logins.getAllLogins()).length, 2);
     ok(await engine._store.itemExists(guid));
 
@@ -401,7 +406,6 @@ add_task(async function test_sync_outgoing() {
 
     // All of these should not include the deleted login. Only the FxA password should exist.
     equal(Services.logins.countLogins("", "", ""), 1);
-    equal(Services.logins.findLogins("", "", "").length, 1);
     equal((await Services.logins.getAllLogins()).length, 1);
     ok(!(await engine._store.itemExists(guid)));
 
@@ -457,7 +461,9 @@ add_task(async function test_sync_incoming() {
     _("Perform sync when remote login has been added");
     await sync_engine_and_validate_telem(engine, false);
 
-    let logins = Services.logins.findLogins("https://www.example.com", "", "");
+    let logins = await Services.logins.searchLoginsAsync({
+      origin: "https://www.example.com",
+    });
     equal(logins.length, 1);
 
     equal(logins[0].QueryInterface(Ci.nsILoginMetaInfo).guid, guid1);
@@ -482,7 +488,9 @@ add_task(async function test_sync_incoming() {
     await engine.setLastSync(newTime / 1000 - 30);
     await sync_engine_and_validate_telem(engine, false);
 
-    logins = Services.logins.findLogins("https://www.example.com", "", "");
+    logins = await Services.logins.searchLoginsAsync({
+      origin: "https://www.example.com",
+    });
     equal(logins.length, 1);
 
     details.password = "alpaca";
@@ -508,7 +516,9 @@ add_task(async function test_sync_incoming() {
     await engine.setLastSync(newTime / 1000 - 30);
     await sync_engine_and_validate_telem(engine, false);
 
-    logins = Services.logins.findLogins("https://www.example.com", "", "");
+    logins = await Services.logins.searchLoginsAsync({
+      origin: "https://www.example.com",
+    });
     equal(logins.length, 1);
 
     details.username = "guanaco";
@@ -534,7 +544,9 @@ add_task(async function test_sync_incoming() {
     await engine.setLastSync(newTime / 1000 - 30);
     await sync_engine_and_validate_telem(engine, false);
 
-    logins = Services.logins.findLogins("https://www.example.com", "", "");
+    logins = await Services.logins.searchLoginsAsync({
+      origin: "https://www.example.com",
+    });
     equal(logins.length, 0);
   } finally {
     await cleanup(engine, server);
@@ -574,7 +586,9 @@ add_task(async function test_sync_incoming_deleted() {
     _("Perform sync when remote login has been deleted");
     await sync_engine_and_validate_telem(engine, false);
 
-    let logins = Services.logins.findLogins("https://www.example.org", "", "");
+    let logins = await Services.logins.searchLoginsAsync({
+      origin: "https://www.example.com",
+    });
     equal(logins.length, 0);
     ok(!(await engine._store.getAllIDs())[guid1]);
     ok(!(await engine._store.itemExists(guid1)));
@@ -631,7 +645,9 @@ add_task(async function test_sync_incoming_deleted_localchanged_remotenewer() {
     );
     await sync_engine_and_validate_telem(engine, false);
 
-    let logins = Services.logins.findLogins("http://mozilla.com", "", "");
+    let logins = await Services.logins.searchLoginsAsync({
+      origin: "https://mozilla.com",
+    });
     equal(logins.length, 0);
     ok(await engine._store.getAllIDs());
   } finally {
@@ -687,7 +703,9 @@ add_task(async function test_sync_incoming_deleted_localchanged_localnewer() {
     );
     await sync_engine_and_validate_telem(engine, false);
 
-    let logins = Services.logins.findLogins("http://www.mozilla.com", "", "");
+    let logins = await Services.logins.searchLoginsAsync({
+      origin: "http://www.mozilla.com",
+    });
     equal(logins.length, 1);
     equal(logins[0].password, "cheetah");
     equal(logins[0].syncCounter, 0);
@@ -734,7 +752,9 @@ add_task(async function test_password_dupe() {
     _("Perform sync");
     await sync_engine_and_validate_telem(engine, true);
 
-    let logins = Services.logins.findLogins("https://www.example.com", "", "");
+    let logins = await Services.logins.searchLoginsAsync({
+      origin: "https://www.example.com",
+    });
 
     equal(logins.length, 1);
     equal(logins[0].QueryInterface(Ci.nsILoginMetaInfo).guid, guid2);
@@ -788,11 +808,9 @@ add_task(async function test_updated_null_password_sync() {
     _("Perform sync");
     await sync_engine_and_validate_telem(engine, false);
 
-    let logins = Services.logins.findLogins(
-      "https://www.nullupdateexample.com",
-      "",
-      ""
-    );
+    let logins = await Services.logins.searchLoginsAsync({
+      origin: "https://www.nullupdateexample.com",
+    });
 
     equal(logins.length, 1);
     equal(logins[0].QueryInterface(Ci.nsILoginMetaInfo).guid, guid1);
@@ -845,11 +863,9 @@ add_task(async function test_updated_undefined_password_sync() {
     _("Perform sync");
     await sync_engine_and_validate_telem(engine, false);
 
-    let logins = Services.logins.findLogins(
-      "https://www.undefinedupdateexample.com",
-      "",
-      ""
-    );
+    let logins = await Services.logins.searchLoginsAsync({
+      origin: "https://www.undefinedupdateexample.com",
+    });
 
     equal(logins.length, 1);
     equal(logins[0].QueryInterface(Ci.nsILoginMetaInfo).guid, guid1);
@@ -887,7 +903,9 @@ add_task(async function test_new_null_password_sync() {
     _("Perform sync");
     await sync_engine_and_validate_telem(engine, false);
 
-    let logins = Services.logins.findLogins("https://www.example.com", "", "");
+    let logins = await Services.logins.searchLoginsAsync({
+      origin: "https://www.example.com",
+    });
 
     equal(logins.length, 1);
     notEqual(logins[0].QueryInterface(Ci.nsILoginMetaInfo).username, null);
@@ -927,7 +945,9 @@ add_task(async function test_new_undefined_password_sync() {
     _("Perform sync");
     await sync_engine_and_validate_telem(engine, false);
 
-    let logins = Services.logins.findLogins("https://www.example.com", "", "");
+    let logins = await Services.logins.searchLoginsAsync({
+      origin: "https://www.example.com",
+    });
 
     equal(logins.length, 1);
     notEqual(logins[0].QueryInterface(Ci.nsILoginMetaInfo).username, null);
@@ -1002,7 +1022,9 @@ add_task(async function test_roundtrip_unknown_fields() {
     props.setProperty("timePasswordChanged", localPasswordChangeTime);
     Services.logins.modifyLogin(login, props);
 
-    let logins = Services.logins.findLogins("https://mozilla.com", "", "");
+    let logins = await Services.logins.searchLoginsAsync({
+      origin: "https://mozilla.com",
+    });
     equal(logins.length, 1, "Should find old login in login manager");
     oldLogin = logins[0].QueryInterface(Ci.nsILoginMetaInfo);
     equal(oldLogin.timePasswordChanged, localPasswordChangeTime);
@@ -1032,7 +1054,9 @@ add_task(async function test_roundtrip_unknown_fields() {
   try {
     await sync_engine_and_validate_telem(engine, false);
 
-    let logins = Services.logins.findLogins("https://mozilla.com", "", "");
+    let logins = await Services.logins.searchLoginsAsync({
+      origin: "https://mozilla.com",
+    });
     equal(
       logins[0].password,
       "n3wpa55",
diff --git a/services/sync/tests/unit/test_password_store.js b/services/sync/tests/unit/test_password_store.js
index e0a4e1343f86..ed393d624189 100644
--- a/services/sync/tests/unit/test_password_store.js
+++ b/services/sync/tests/unit/test_password_store.js
@@ -24,11 +24,10 @@ async function checkRecord(
   let engine = Service.engineManager.get("passwords");
   let store = engine._store;
 
-  let logins = Services.logins.findLogins(
-    record.hostname,
-    record.formSubmitURL,
-    null
-  );
+  let logins = await Services.logins.searchLoginsAsync({
+    origin: record.hostname,
+    formActionOrigin: record.formSubmitURL,
+  });
 
   _("Record" + name + ":" + JSON.stringify(logins));
   _("Count" + name + ":" + logins.length);
@@ -350,16 +349,15 @@ add_task(async function run_test() {
     );
 
     // Only the good record makes it to Services.logins.
-    let badLogins = Services.logins.findLogins(
-      recordA.hostname,
-      recordA.formSubmitURL,
-      recordA.httpRealm
-    );
-    let goodLogins = Services.logins.findLogins(
-      recordB.hostname,
-      recordB.formSubmitURL,
-      null
-    );
+    let badLogins = await Services.logins.searchLoginsAsync({
+      origin: recordA.hostname,
+      formActionOrigin: recordA.formSubmitURL,
+      httpRealm: recordA.httpRealm,
+    });
+    let goodLogins = await Services.logins.searchLoginsAsync({
+      origin: recordB.hostname,
+      formActionOrigin: recordB.formSubmitURL,
+    });
 
     _("Bad: " + JSON.stringify(badLogins));
     _("Good: " + JSON.stringify(goodLogins));
diff --git a/services/sync/tps/extensions/tps/resource/modules/passwords.sys.mjs b/services/sync/tps/extensions/tps/resource/modules/passwords.sys.mjs
index 9d1484773cff..976755e9892a 100644
--- a/services/sync/tps/extensions/tps/resource/modules/passwords.sys.mjs
+++ b/services/sync/tps/extensions/tps/resource/modules/passwords.sys.mjs
@@ -112,12 +112,12 @@ Password.prototype = {
    *
    * @return the guid of the password if found, otherwise -1
    */
-  Find() {
-    let logins = Services.logins.findLogins(
-      this.props.hostname,
-      this.props.submitURL,
-      this.props.realm
-    );
+  async Find() {
+    let logins = await Services.logins.searchLoginsAsync({
+      origin: this.props.hostname,
+      formActionOrigin: this.props.submitURL,
+      httpRealm: this.props.realm,
+    });
     for (var i = 0; i < logins.length; i++) {
       if (
         logins[i].username == this.props.username &&
diff --git a/services/sync/tps/extensions/tps/resource/tps.sys.mjs b/services/sync/tps/extensions/tps/resource/tps.sys.mjs
index 7ca1ee055c89..d975b766cd51 100644
--- a/services/sync/tps/extensions/tps/resource/tps.sys.mjs
+++ b/services/sync/tps/extensions/tps/resource/tps.sys.mjs
@@ -464,19 +464,19 @@ export var TPS = {
             break;
           case ACTION_VERIFY:
             lazy.Logger.AssertTrue(
-              passwordOb.Find() != -1,
+              (await passwordOb.Find()) != -1,
               "password not found"
             );
             break;
           case ACTION_VERIFY_NOT:
             lazy.Logger.AssertTrue(
-              passwordOb.Find() == -1,
+              (await passwordOb.Find()) == -1,
               "password found, but it shouldn't exist"
             );
             break;
           case ACTION_DELETE:
             lazy.Logger.AssertTrue(
-              passwordOb.Find() != -1,
+              (await passwordOb.Find()) != -1,
               "password not found"
             );
             passwordOb.Remove();
@@ -484,7 +484,7 @@ export var TPS = {
           case ACTION_MODIFY:
             if (passwordOb.updateProps != null) {
               lazy.Logger.AssertTrue(
-                passwordOb.Find() != -1,
+                (await passwordOb.Find()) != -1,
                 "password not found"
               );
               passwordOb.Update();
diff --git a/toolkit/components/forgetaboutsite/test/unit/test_removeDataFromDomain.js b/toolkit/components/forgetaboutsite/test/unit/test_removeDataFromDomain.js
index f686627f956d..84894d1ec551 100644
--- a/toolkit/components/forgetaboutsite/test/unit/test_removeDataFromDomain.js
+++ b/toolkit/components/forgetaboutsite/test/unit/test_removeDataFromDomain.js
@@ -108,7 +108,7 @@ function check_disabled_host(aHost, aIsDisabled) {
  *        The host to add the login for.
  */
 async function add_login(aHost) {
-  check_login_exists(aHost, false);
+  await check_login_exists(aHost, false);
   let login = Cc["@mozilla.org/login-manager/loginInfo;1"].createInstance(
     Ci.nsILoginInfo
   );
@@ -122,7 +122,7 @@ async function add_login(aHost) {
     LOGIN_PASSWORD_FIELD
   );
   await Services.logins.addLoginAsync(login);
-  check_login_exists(aHost, true);
+  await check_login_exists(aHost, true);
 }
 
 /**
@@ -133,8 +133,8 @@ async function add_login(aHost) {
  * @param aExists
  *        True if the login should exist, false otherwise.
  */
-function check_login_exists(aHost, aExists) {
-  let logins = Services.logins.findLogins(aHost, "", null);
+async function check_login_exists(aHost, aExists) {
+  let logins = await Services.logins.searchLoginsAsync({ origin: aHost });
   Assert.equal(logins.length, aExists ? 1 : 0);
 }
 
@@ -314,24 +314,24 @@ async function test_login_manager_logins_cleared_with_direct_match() {
   const TEST_HOST = "http://mozilla.org";
   await add_login(TEST_HOST);
   await ForgetAboutSite.removeDataFromDomain("mozilla.org");
-  check_login_exists(TEST_HOST, true);
+  await check_login_exists(TEST_HOST, true);
 }
 
 async function test_login_manager_logins_cleared_with_subdomain() {
   const TEST_HOST = "http://www.mozilla.org";
   await add_login(TEST_HOST);
   await ForgetAboutSite.removeDataFromDomain("mozilla.org");
-  check_login_exists(TEST_HOST, true);
+  await check_login_exists(TEST_HOST, true);
 }
 
 async function test_login_manager_logins_not_cleared_with_uri_contains_domain() {
   const TEST_HOST = "http://ilovemozilla.org";
   await add_login(TEST_HOST);
   await ForgetAboutSite.removeDataFromDomain("mozilla.org");
-  check_login_exists(TEST_HOST, true);
+  await check_login_exists(TEST_HOST, true);
 
   Services.logins.removeAllUserFacingLogins();
-  check_login_exists(TEST_HOST, false);
+  await check_login_exists(TEST_HOST, false);
 }
 
 async function test_login_manager_disabled_hosts_cleared_base_domain() {
diff --git a/toolkit/components/passwordmgr/LoginHelper.sys.mjs b/toolkit/components/passwordmgr/LoginHelper.sys.mjs
index f4556b09a96d..6108a2aada02 100644
--- a/toolkit/components/passwordmgr/LoginHelper.sys.mjs
+++ b/toolkit/components/passwordmgr/LoginHelper.sys.mjs
@@ -171,14 +171,14 @@ class ImportRowProcessor {
    *        A login object.
    * @returns {boolean} True if the entry is similar or identical to another previously processed entry, false otherwise.
    */
-  checkConflictingWithExistingLogins(login) {
+  async checkConflictingWithExistingLogins(login) {
     // While here we're passing formActionOrigin and httpRealm, they could be empty/null and get
     // ignored in that case, leading to multiple logins for the same username.
-    let existingLogins = Services.logins.findLogins(
-      login.origin,
-      login.formActionOrigin,
-      login.httpRealm
-    );
+    let existingLogins = await Services.logins.searchLoginsAsync({
+      origin: login.origin,
+      httpRealm: login.httpRealm,
+    });
+
     // Check for an existing login that matches *including* the password.
     // If such a login exists, we do not need to add a new login.
     if (
@@ -1498,7 +1498,7 @@ export const LoginHelper = {
         if (processor.checkConflictingOriginWithPreviousRows(login)) {
           continue;
         }
-        if (processor.checkConflictingWithExistingLogins(login)) {
+        if (await processor.checkConflictingWithExistingLogins(login)) {
           continue;
         }
         processor.addLoginToSummary(login, "added");
diff --git a/toolkit/components/passwordmgr/LoginManagerAuthPrompter.sys.mjs b/toolkit/components/passwordmgr/LoginManagerAuthPrompter.sys.mjs
index 3aa05d4a2714..8c39cf09b9b6 100644
--- a/toolkit/components/passwordmgr/LoginManagerAuthPrompter.sys.mjs
+++ b/toolkit/components/passwordmgr/LoginManagerAuthPrompter.sys.mjs
@@ -417,7 +417,13 @@ LoginManagerAuthPrompter.prototype = {
       }
 
       // Look for existing logins.
-      foundLogins = Services.logins.findLogins(origin, null, realm);
+      // We don't use searchLoginsAsync here and in asyncPromptPassword
+      // because of bug 1848682
+      let matchData = lazy.LoginHelper.newPropertyBag({
+        origin,
+        httpRealm: realm,
+      });
+      foundLogins = Services.logins.searchLogins(matchData);
 
       // XXX Like the original code, we can't deal with multiple
       // account selection. (bug 227632)
@@ -531,7 +537,11 @@ LoginManagerAuthPrompter.prototype = {
         Services.logins.getLoginSavingEnabled(origin);
       if (!aPassword.value) {
         // Look for existing logins.
-        var foundLogins = Services.logins.findLogins(origin, null, realm);
+        let matchData = lazy.LoginHelper.newPropertyBag({
+          origin,
+          httpRealm: realm,
+        });
+        let foundLogins = Services.logins.searchLogins(matchData);
 
         // XXX Like the original code, we can't deal with multiple
         // account selection (bug 227632). We can deal with finding the
diff --git a/toolkit/components/passwordmgr/nsILoginManager.idl b/toolkit/components/passwordmgr/nsILoginManager.idl
index 3001355aa545..d9c1571485f4 100644
--- a/toolkit/components/passwordmgr/nsILoginManager.idl
+++ b/toolkit/components/passwordmgr/nsILoginManager.idl
@@ -195,7 +195,8 @@ interface nsILoginManager : nsISupports {
    * Search for logins matching the specified criteria. Called when looking
    * for logins that might be applicable to a form or authentication request.
    *
-   * @deprecated Use `searchLoginsAsync` instead.
+   * @deprecated Use `searchLoginsAsync` instead. This function is retained
+   * for Thunderbird compatibility.
    *
    * @param aOrigin
    *        The origin to restrict searches to. For example: "http://www.site.com".
diff --git a/toolkit/components/passwordmgr/storage-json.sys.mjs b/toolkit/components/passwordmgr/storage-json.sys.mjs
index 6c249b1423be..f5c1399c1f42 100644
--- a/toolkit/components/passwordmgr/storage-json.sys.mjs
+++ b/toolkit/components/passwordmgr/storage-json.sys.mjs
@@ -286,12 +286,12 @@ export class LoginManagerStorage_json {
     const resultLogins = [];
     for (const [login, encryptedLogin] of encryptedLogins) {
       // check for duplicates
-      const { origin, formActionOrigin, httpRealm } = login;
-      const existingLogins = this.findLogins(
-        origin,
-        formActionOrigin,
-        httpRealm
-      );
+      let loginData = {
+        origin: login.origin,
+        httpRealm: login.httpRealm,
+      };
+      const existingLogins = await Services.logins.searchLoginsAsync(loginData);
+
       const matchingLogin = existingLogins.find(l => login.matches(l, true));
       if (matchingLogin) {
         if (continueOnDuplicates) {
@@ -372,10 +372,13 @@ export class LoginManagerStorage_json {
 
     // Look for an existing entry in case key properties changed.
     if (!newLogin.matches(oldLogin, true)) {
-      let logins = this.findLogins(
-        newLogin.origin,
-        newLogin.formActionOrigin,
-        newLogin.httpRealm
+      let loginData = {
+        origin: newLogin.origin,
+        httpRealm: newLogin.httpRealm,
+      };
+
+      let logins = this.searchLogins(
+        lazy.LoginHelper.newPropertyBag(loginData)
       );
 
       let matchingLogin = logins.find(login => newLogin.matches(login, true));
diff --git a/toolkit/components/passwordmgr/test/mochitest/test_prompt_promptAuth_proxy.html b/toolkit/components/passwordmgr/test/mochitest/test_prompt_promptAuth_proxy.html
index a7cec2d0b93c..6f78d62f1b10 100644
--- a/toolkit/components/passwordmgr/test/mochitest/test_prompt_promptAuth_proxy.html
+++ b/toolkit/components/passwordmgr/test/mochitest/test_prompt_promptAuth_proxy.html
@@ -63,8 +63,8 @@ let chromeScript = runInParent(() => {
     };
   });
 
-  addMessageListener("getTimeLastUsed", () => {
-    let logins = Services.logins.findLogins(mozproxyURL, null, "Proxy Realm");
+  addMessageListener("getTimeLastUsed", async () => {
+    let logins = await Services.logins.searchLoginsAsync({ origin: mozproxyURL, httpRealm: "Proxy Realm"});
     return logins[0].QueryInterface(Ci.nsILoginMetaInfo).timeLastUsed;
   });
 
diff --git a/toolkit/components/passwordmgr/test/unit/test_legacy_empty_formActionOrigin.js b/toolkit/components/passwordmgr/test/unit/test_legacy_empty_formActionOrigin.js
index ec6846ab9fbd..d630ed0e078c 100644
--- a/toolkit/components/passwordmgr/test/unit/test_legacy_empty_formActionOrigin.js
+++ b/toolkit/components/passwordmgr/test/unit/test_legacy_empty_formActionOrigin.js
@@ -65,7 +65,7 @@ add_task(async function test_addLogin_wildcard() {
 });
 
 /**
- * Verifies that findLogins, searchLogins, and countLogins include all logins
+ * Verifies that searchLogins and countLogins include all logins
  * that have an empty formActionOrigin in the store, even when a formActionOrigin is
  * specified.
  */
@@ -76,11 +76,6 @@ add_task(function test_search_all_wildcard() {
   });
   Assert.equal(Services.logins.searchLogins(matchData).length, 2);
 
-  Assert.equal(
-    Services.logins.findLogins("", "http://www.example.com", null).length,
-    2
-  );
-
   Assert.equal(
     Services.logins.countLogins("", "http://www.example.com", null),
     2
@@ -90,15 +85,6 @@ add_task(function test_search_all_wildcard() {
   matchData.setProperty("origin", "http://any.example.com");
   Assert.equal(Services.logins.searchLogins(matchData).length, 1);
 
-  Assert.equal(
-    Services.logins.findLogins(
-      "http://any.example.com",
-      "http://www.example.com",
-      null
-    ).length,
-    1
-  );
-
   Assert.equal(
     Services.logins.countLogins(
       "http://any.example.com",
diff --git a/toolkit/components/passwordmgr/test/unit/test_logins_decrypt_failure.js b/toolkit/components/passwordmgr/test/unit/test_logins_decrypt_failure.js
index eeca48cee591..533bd9dd8de5 100644
--- a/toolkit/components/passwordmgr/test/unit/test_logins_decrypt_failure.js
+++ b/toolkit/components/passwordmgr/test/unit/test_logins_decrypt_failure.js
@@ -35,9 +35,8 @@ add_task(async function test_logins_decrypt_failure() {
 
   // These functions don't see the non-decryptable entries anymore.
   let savedLogins = await Services.logins.getAllLogins();
-  Assert.equal(savedLogins.length, 0);
   Assert.equal(savedLogins.length, 0, "getAllLogins length");
-  Assert.equal(Services.logins.findLogins("", "", "").length, 0);
+  await Assert.rejects(Services.logins.searchLoginsAsync({}), /is required/);
   Assert.equal(Services.logins.searchLogins(newPropertyBag()).length, 0);
   Assert.throws(
     () => Services.logins.modifyLogin(logins[0], newPropertyBag()),
@@ -63,7 +62,11 @@ add_task(async function test_logins_decrypt_failure() {
 
   // Finding logins doesn't return the non-decryptable duplicates.
   Assert.equal(
-    Services.logins.findLogins("http://www.example.com", "", "").length,
+    (
+      await Services.logins.searchLoginsAsync({
+        origin: "http://www.example.com",
+      })
+    ).length,
     1
   );
   let matchData = newPropertyBag({ origin: "http://www.example.com" });
diff --git a/toolkit/components/passwordmgr/test/unit/test_logins_metainfo.js b/toolkit/components/passwordmgr/test/unit/test_logins_metainfo.js
index 6a73b2019926..e85156498162 100644
--- a/toolkit/components/passwordmgr/test/unit/test_logins_metainfo.js
+++ b/toolkit/components/passwordmgr/test/unit/test_logins_metainfo.js
@@ -17,8 +17,8 @@ const gLooksLikeUUIDRegex = /^\{\w{8}-\w{4}-\w{4}-\w{4}-\w{12}\}$/;
  * the given nsILoginInfo.  In case there is more than one login for the
  * origin, the test fails.
  */
-function retrieveLoginMatching(aLoginInfo) {
-  let logins = Services.logins.findLogins(aLoginInfo.origin, "", "");
+async function retrieveOriginMatching(origin) {
+  let logins = await Services.logins.searchLoginsAsync({ origin });
   Assert.equal(logins.length, 1);
   return logins[0].QueryInterface(Ci.nsILoginMetaInfo);
 }
@@ -94,7 +94,7 @@ add_task(async function test_addLogin_metainfo() {
   Assert.equal(gLoginInfo1.timesUsed, 0);
 
   // A login with valid metadata should have been stored.
-  gLoginMetaInfo1 = retrieveLoginMatching(gLoginInfo1);
+  gLoginMetaInfo1 = await retrieveOriginMatching(gLoginInfo1.origin);
   Assert.ok(gLooksLikeUUIDRegex.test(gLoginMetaInfo1.guid));
   let creationTime = gLoginMetaInfo1.timeCreated;
   LoginTestUtils.assertTimeIsAboutNow(creationTime);
@@ -110,12 +110,12 @@ add_task(async function test_addLogin_metainfo() {
   assertMetaInfoEqual(gLoginInfo2, originalLogin);
 
   // A login with the provided metadata should have been stored.
-  gLoginMetaInfo2 = retrieveLoginMatching(gLoginInfo2);
+  gLoginMetaInfo2 = await retrieveOriginMatching(gLoginInfo2.origin);
   assertMetaInfoEqual(gLoginMetaInfo2, gLoginInfo2);
 
   // Add an authentication login to the database before continuing.
   await Services.logins.addLoginAsync(gLoginInfo3);
-  gLoginMetaInfo3 = retrieveLoginMatching(gLoginInfo3);
+  gLoginMetaInfo3 = await retrieveOriginMatching(gLoginInfo3.origin);
   await LoginTestUtils.checkLogins([gLoginInfo1, gLoginInfo2, gLoginInfo3]);
 });
 
@@ -140,7 +140,7 @@ add_task(async function test_addLogin_metainfo_duplicate() {
  * Tests that the existing metadata is not changed when modifyLogin is called
  * with an nsILoginInfo argument.
  */
-add_task(function test_modifyLogin_nsILoginInfo_metainfo_ignored() {
+add_task(async function test_modifyLogin_nsILoginInfo_metainfo_ignored() {
   let newLoginInfo = gLoginInfo1.clone().QueryInterface(Ci.nsILoginMetaInfo);
   newLoginInfo.guid = Services.uuid.generateUUID().toString();
   newLoginInfo.timeCreated = Date.now();
@@ -149,14 +149,14 @@ add_task(function test_modifyLogin_nsILoginInfo_metainfo_ignored() {
   newLoginInfo.timesUsed = 12;
   Services.logins.modifyLogin(gLoginInfo1, newLoginInfo);
 
-  newLoginInfo = retrieveLoginMatching(gLoginInfo1);
+  newLoginInfo = await retrieveOriginMatching(gLoginInfo1.origin);
   assertMetaInfoEqual(newLoginInfo, gLoginMetaInfo1);
 });
 
 /**
  * Tests the modifyLogin function with an nsIProperyBag argument.
  */
-add_task(function test_modifyLogin_nsIProperyBag_metainfo() {
+add_task(async function test_modifyLogin_nsIProperyBag_metainfo() {
   // Use a new reference time that is two minutes from now.
   let newTimeMs = Date.now() + 120000;
   let newUUIDValue = Services.uuid.generateUUID().toString();
@@ -173,7 +173,7 @@ add_task(function test_modifyLogin_nsIProperyBag_metainfo() {
     })
   );
 
-  gLoginMetaInfo1 = retrieveLoginMatching(gLoginInfo1);
+  gLoginMetaInfo1 = await retrieveOriginMatching(gLoginInfo1.origin);
   Assert.equal(gLoginMetaInfo1.guid, newUUIDValue);
   Assert.equal(gLoginMetaInfo1.timeCreated, newTimeMs);
   Assert.equal(gLoginMetaInfo1.timeLastUsed, newTimeMs + 2);
@@ -190,7 +190,7 @@ add_task(function test_modifyLogin_nsIProperyBag_metainfo() {
   );
   gLoginInfo2.password = "new password";
 
-  gLoginMetaInfo2 = retrieveLoginMatching(gLoginInfo2);
+  gLoginMetaInfo2 = await retrieveOriginMatching(gLoginInfo2.origin);
   Assert.equal(gLoginMetaInfo2.password, gLoginInfo2.password);
   Assert.equal(gLoginMetaInfo2.timeCreated, originalLogin.timeCreated);
   Assert.equal(gLoginMetaInfo2.timeLastUsed, originalLogin.timeLastUsed);
@@ -207,7 +207,7 @@ add_task(function test_modifyLogin_nsIProperyBag_metainfo() {
   );
   gLoginInfo2.password = "other password";
 
-  gLoginMetaInfo2 = retrieveLoginMatching(gLoginInfo2);
+  gLoginMetaInfo2 = await retrieveOriginMatching(gLoginInfo2.origin);
   Assert.equal(gLoginMetaInfo2.password, gLoginInfo2.password);
   Assert.equal(gLoginMetaInfo2.timeCreated, originalLogin.timeCreated);
   Assert.equal(gLoginMetaInfo2.timeLastUsed, originalLogin.timeLastUsed);
@@ -221,7 +221,7 @@ add_task(function test_modifyLogin_nsIProperyBag_metainfo() {
     })
   );
 
-  gLoginMetaInfo2 = retrieveLoginMatching(gLoginInfo2);
+  gLoginMetaInfo2 = await retrieveOriginMatching(gLoginInfo2.origin);
   Assert.equal(gLoginMetaInfo2.timeCreated, originalLogin.timeCreated);
   Assert.equal(gLoginMetaInfo2.timeLastUsed, originalLogin.timeLastUsed);
   Assert.equal(gLoginMetaInfo2.timePasswordChanged, newTimeMs);
@@ -289,7 +289,16 @@ add_task(async function test_storage_metainfo() {
   await LoginTestUtils.reloadData();
   await LoginTestUtils.checkLogins([gLoginInfo1, gLoginInfo2, gLoginInfo3]);
 
-  assertMetaInfoEqual(retrieveLoginMatching(gLoginInfo1), gLoginMetaInfo1);
-  assertMetaInfoEqual(retrieveLoginMatching(gLoginInfo2), gLoginMetaInfo2);
-  assertMetaInfoEqual(retrieveLoginMatching(gLoginInfo3), gLoginMetaInfo3);
+  assertMetaInfoEqual(
+    await retrieveOriginMatching(gLoginInfo1.origin),
+    gLoginMetaInfo1
+  );
+  assertMetaInfoEqual(
+    await retrieveOriginMatching(gLoginInfo2.origin),
+    gLoginMetaInfo2
+  );
+  assertMetaInfoEqual(
+    await retrieveOriginMatching(gLoginInfo3.origin),
+    gLoginMetaInfo3
+  );
 });
diff --git a/toolkit/components/passwordmgr/test/unit/test_logins_search.js b/toolkit/components/passwordmgr/test/unit/test_logins_search.js
index 89337f872ec6..b69ec16ff833 100644
--- a/toolkit/components/passwordmgr/test/unit/test_logins_search.js
+++ b/toolkit/components/passwordmgr/test/unit/test_logins_search.js
@@ -1,6 +1,5 @@
 /**
- * Tests methods that find specific logins in the store (findLogins,
- * searchLogins, and countLogins).
+ * Tests methods that find specific logins in the store (searchLogins and countLogins).
  *
  * The getAllLogins method is not tested explicitly here, because it is used by
  * all tests to verify additions, removals and modifications to the login store.
@@ -47,11 +46,11 @@ function checkSearchLogins(aQuery, aExpectedCount) {
 }
 
 /**
- * Tests findLogins, searchLogins, and countLogins with the same query.
+ * Tests searchLogins, and countLogins with the same query.
  *
  * @param aQuery
  *        The "origin", "formActionOrigin", and "httpRealm" properties of this
- *        object are passed as parameters to findLogins and countLogins.  The
+ *        object are passed as parameters to countLogins.  The
  *        same object is then passed to the checkSearchLogins function.
  * @param aExpectedCount
  *        Number of logins from the test data that should be found.  The actual
@@ -65,7 +64,7 @@ function checkAllSearches(aQuery, aExpectedCount) {
   let expectedLogins = buildExpectedLogins(aQuery);
   Assert.equal(expectedLogins.length, aExpectedCount);
 
-  // The findLogins and countLogins functions support wildcard matches by
+  // The countLogins function support wildcard matches by
   // specifying empty strings as parameters, while searchLogins requires
   // omitting the property entirely.
   let origin = "origin" in aQuery ? aQuery.origin : "";
@@ -73,10 +72,6 @@ function checkAllSearches(aQuery, aExpectedCount) {
     "formActionOrigin" in aQuery ? aQuery.formActionOrigin : "";
   let httpRealm = "httpRealm" in aQuery ? aQuery.httpRealm : "";
 
-  // Test findLogins.
-  let logins = Services.logins.findLogins(origin, formActionOrigin, httpRealm);
-  LoginTestUtils.assertLoginListsEqual(logins, expectedLogins);
-
   // Test countLogins.
   let count = Services.logins.countLogins(origin, formActionOrigin, httpRealm);
   Assert.equal(count, expectedLogins.length);
@@ -95,7 +90,7 @@ add_setup(async () => {
 });
 
 /**
- * Tests findLogins, searchLogins, and countLogins with basic queries.
+ * Tests searchLogins, and countLogins with basic queries.
  */
 add_task(function test_search_all_basic() {
   // Find all logins, using no filters in the search functions.
@@ -217,7 +212,7 @@ add_task(function test_search_all_full_case_sensitive() {
 });
 
 /**
- * Tests findLogins, searchLogins, and countLogins with queries that should
+ * Tests searchLogins, and countLogins with queries that should
  * return no values.
  */
 add_task(function test_search_all_empty() {